Bullet projectile resistant structures are made with many materials. A brick wall of a thickness of 24 cm, for example, is projectile resistant. However, the brick wall has many disadvantages compared to a drywall construction. Herein, the term drywall structure or dry wall construction denotes any structure or building construction with a frame substructure with building panels or boards mounted thereto. The static advantage of a drywall compared to a brick wall is due to its reduced weight. Most walls in a building do have to withstand any forces from above so they can be built as drywall construction of comparably low weight
Handgun bullet projectile resistant drywall structures are known in the state of the art. A conventional handgun bullet projectile resistant partition wall structure comprises a substructure of drywall profiles (metal profiles) which form upright studs. The upright studs are fixed to drywall profiles which are mounted horizontally, extending from the bottom to the raw ceiling. Typically, the distance between adjacent upright studs is about 65 cm. The upright studs comprise parallel extending flange portions having an outer surface capable of attaching boards (building panels) thereto. Both parallel extending flanges are connected via a base portion. The parallel extending flanges and the base portion can be arranged in a C-form or a U-form.
To achieve the handgun bullet projectile resistance for a separation wall, it is known to arrange inside the substructure, i.e. only in the space formed between the base portions of adjacent drywall profiles, gypsum fiber boards. Inside the substructure (separation wall) means that the gypsum fiber boards are arranged so as to extend between the drywall profiles, only. The gypsum fiber boards stand between the base portions. It is uncommon to fix gypsum fiber boards to the flange portions of a substructure because of their high weight compared to a gypsum plasterboard. For example, the gypsum fiber board with the product name Knauf “Torro” has an areal density of 42 kg/m2. Moreover, the gypsum fiber boards cannot be mounted like gypsum plasterboards since conventional screwing is not possible without pre-drilling.
Known structures provide projectile resistance performance of class FB4 (BR4 English language equivalent) according to ballistic standard DIN EN 1522 which is the highest class of protection against hand guns. EN 1522 is the Euro-norm standard for bullet resistance by which structures are tested and rated. Class FB4 (BR4) resists 3 shots of a handgun 0.44 Magnum FJ (Full Metal Jacket)/FN (Flat Nose)/SC (Soft Core) of the weight 15.6±0.1 g from a range of 5.00±0.5 m having a velocity of 440±10 m/s and an impact energy of 1510 J.
Tests have shown that conventional separation wall structures of the above described type are not suitable for bullet projectile resistance of higher classes. In fact, test shots with a rifle, in particular the sizes of the formed shot channels, on those handgun bullet projectile resistant drywall structures lead to the impression that no drywall construction would stand a rifle bullet projectile. The next class higher than FB4 is FB 5 (BR5) which is the first class for the resistance against rifle bullets. FB5 structures resist three shots from a rifle in caliber 5.56×45 mm NATO FJ (Full Metal Jacket)/PB (Pointed Bullet)/SCP (Soft Core (lead) & Steel Penetrator) of the weight 4.0±0.1 g from a range 10.00±0.5 m having a velocity of 950±10 m/s with an impact energy of 1800 J.
There is a strong need for drywall constructions with increased bullet resistance compared to the state of the art. Killing sprees and terrorizing assaults are mostly carried out by use of rifles. Hence the handgun bullet projectile resistance is not sufficient and structures with rifle bullet projectile resistance are required. One specific field of application are structures in public buildings (schools, police stations, court buildings, etc.). Further fields of application are easily conceivable.